This invention relates generally to an automatic chuck structure as would be used in, but not limited to, a multi-station rotary turret type of automatic capping machine. More specifically, the present invention relates to an internally gripping chuck structure which grips a closure internally and inserts it into the upper portion of a container.
In certain types of machines for applying closures to containers, there is employed a rotary turret having a series of capping stations around its periphery which vertically reciprocate attached chuck means to pick up each closure and to seat the latter into or onto the upper portion of a container. For handling non-rotative closures with such machines it has been expedient to employ some adaptation of the externally gripping chuck shown in FIGS. 16 through 22 of U.S. Pat. No. 3,616,513 to Dimond, issued to the same assignee as the present invention.
Although various versions of the U.S. Pat. No. 3,616,513 chuck have been devised, it is not entirely suitable for the particular bottle and internal plug used as example herein. This bottle is a flexible one which, without special support, would collapse under the thrust of plug insertion.
The bottle has an integrally moulded collar around its neck portion to receive the required support from suitable means during plug insertion. The level of this collar is such that the supporting plane is only about 3/16 inch below the bottom of the inserted plug. The U.S. Pat. No. 3,616,513 chuck typically requires at least 3/16 inch spindle over-travel to stabilize the jaws in released condition before upward withdrawl. In practice, however, at least 1/4 inch overtravel must be provided to allow for slight variations in container height so that a possibility of overtravel interference with the supporting plane exists.
Another difficulty associated with prior chucks with respect to the chucking operation considered herein resides in the fact that the externally gripping chuck necessarily would contact the outer surface of the chucked plug and at least a portion of such outer surface comes into sealing contact with the mouth of the bottle. In various situations this could be objectionable on sanitary grounds.